Submersible trim system

Abstract

A trim system for a submersible comprises a ball control system and a hydraulic control system. The ball control system includes a tubular ball transfer line 33 substantially through the length of the vessel, a plurality of high-density, solid balls 34 within the ball transfer line 33 which are moveable to alter the weight distribution, a coil 1 at each end of the ball transfer line 33 as a reservoir for the balls 34, brake device 3 for temporarily fixing the position of the balls and sensing device 5 for determining the location of the balls. The hydraulic control system includes vehicle control unit 27, power transfer unit 13, manifold 2, compensator 20 and various valves, filters 17 and quick disconnects 12 for moving preselected balls through the ball transfer line 33.

We claim: 
     
       1. A trim system for a submersible comprising A. an elongated, ball transfer conduit communicating with the submersible and extending from a first position to a second position;   B. a plurality of unconnected high-density balls within the ball transfer conduit and moveable therein;   C. means for hydraulically moving preselected balls in the ball transfer conduit and altering the weight distribution of the submersible, wherein the high-density balls are spherical and the ball transfer conduit is circular in cross section and they cooperate to form an annular orifice therebetween sufficient to allow the slip flow of hydraulic fluid through the annular orifice.   
     
     
       2. The submersible trim system of claim 1 wherein the ball transfer conduit is between about 7 to 50 mm inside diameter and the high-density, spherical balls are between 0.2-2 mm in diameter smaller than the ball transfer conduit. 
     
     
       3. A trim system for a submersible comprising A. an elongated, ball transfer conduit communicating with the submersible and extending from a first position to a second position;   B. a plurality of high-density balls within the ball transfer conduit and moveable therein;   C. a reservoir for the high-density, spherical balls at each end of the ball transfer conduit near the first and second position;   D. means for hydraulically moving preselected balls in the ball transfer conduit and altering the weight distribution of the submersible, wherein the high-density balls are spherical and the ball transfer conduit is circular in cross section and they cooperate to form an annular orifice therebetween sufficient to allow the flow of hydraulic fluid through the annular orifice.   
     
     
       4. The submersible trim system of claim 3 which further comprises a plurality of low-density, spherical balls within each reservoir and the ball transfer conduit at each end thereof and separated by the high-density, spherical balls, the low-density, spherical balls and high-density, spherical balls being in contact with each adjacent ball to form a string of spherical balls. 
     
     
       5. The submersible trim system of claim 4 which additionally includes a ball piston in each reservoir in contact with the string of spherical balls and comprising frictional drag means, a seal to minimize leakage, a check valve for free flow of hydraulic fluid, and a relief valve to create pressure so each ball piston applies a force against the string of balls to maintain contact between the spherical balls. 
     
     
       6. The submersible trim system of claim 4 wherein the diameter of the low-density, spherical balls is less than the diameter of the high-density, spherical balls. 
     
     
       7. The submersible trim system of claim 3 wherein the reservoir comprises a coil of conduit. 
     
     
       8. The submersible trim system of claim 7 wherein the coil conduit has an inside diameter greater than the diameter of the ball transfer conduit. 
     
     
       9. The submersible trim system of claim 7 which further comprises a plurality of low-density, spherical balls within each coil conduit and the ball transfer conduit at each end thereof and separated in the ball transfer conduit by the high-density, spherical balls. 
     
     
       10. The submersible trim system of claim 9 wherein the diameter of the low-density, spherical balls is less than the diameter of the high-density, spherical balls. 
     
     
       11. The submersible trim system of claim 7 which further comprises brake means in the ball transfer conduit for temporarily fixing the position of the high-density, spherical balls and the low-density, spherical balls therein. 
     
     
       12. The submersible trim system of claim 11 which further comprises a position sensor for mapping the position of any of the high-density, spherical balls, and means communicating with the position sensor for displaying the position of the high-density, spherical balls. 
     
     
       13. A method for altering the trim of a submersible comprising providing an elongated ball transfer conduit in communication with the submersible and extending from a first position to a second position and a string of high-density, spherical balls within the ball transfer conduit, each high-density, spherical ball and the ball transfer conduit cooperating to form an annular orifice therebetween;   changing the distribution of weight of the submersible by hydraulically moving preselected of the high-density, spherical balls in the ball transfer conduit by flowing hydraulic fluid through the annular orifices resulting in a pressure differential from one side of each high-density, spherical ball to the other side;   sensing the location of the high-density, spherical balls in response to the hydraulic movement, and   temporarily fixing the position of the high-density, spherical balls when the desired trim is accomplished.   
     
     
       14. The method of claim 13 for altering the trim of a submersible which additionally includes providing a reservoir for the high-density, spherical balls at each end of the ball transfer conduit near the first and second positions. 
     
     
       15. The method of claim 14 for altering the trim of a submersible which further comprises providing a plurality of low-density, spherical balls within each reservoir and the ball transfer conduit at each end of the string of the high-density, spherical balls. 
     
     
       16. The method of claim 15 for altering the trim of a submersible further comprising providing the low-density, spherical balls with a diameter less than the diameter of the high-density, spherical balls.